After a relationship lasting some ten years, the last few of which were stormy, Frédéric Chopin finally separated from George Sand in July 1847. It was on her estate at Nohant that, over seven summers, he had composed or completed the core of his oeuvre: the Fantaisie Op.49, a dozen mazurkas, the Berceuse, several nocturnes, two of the ballades, two of the scherzos, his last two sonatas, the Trois Nouvelles Études, three impromptus, three waltzes, two polonaises, among others.